1. Technical Field of the Invention
This invention relates to cellular telecommunications systems and, more particularly, to a system and method for defining personal home areas for individual subscribers of telecommunications services.
2. Description of Related Art
As the use of cellular telephones spreads, the number of network operators who compete to provide telecommunication services to subscribers is also increasing. Each operator, moreover, desires to offer unique services which distinguish the operator from its competition. One such way to distinguish the service provided to subscribers is to offer increased levels of individual service tailoring. Individually defined service, however, comes only at the expense of increased data storage and data transmission requirements. Cellular equipment providers have not designed cellular networks to handle many of the contemplated data storage and interchange requirements. As a result, only limited tailoring of individual services has been implemented. For example, operators may now offer subscribers the choice of having cellular service only in a downtown area, or for a higher cost, having service which includes the suburbs as well.
With the advent of personal communication services (PCS), operators desire to offer more complete programs of individual service definition. Under an exemplary plan, a subscriber may be offered cellular services at a flat rate when at home or in his neighborhood, at a reduced rate (per minute) when at work (or at a second home), and at a standard (full) rate elsewhere. The sizes of the "Home" and "Work" areas as well as the rates charged may be individually defined for each subscriber.
In order to implement such a plan, subscribers must be able to designate on an individual basis the areas to be designated as Home and Work. Additionally, the cellular system must be able to determine when the subscriber is located in one of the designated areas, and be able to apply the appropriate billing rate based on the subscriber's location. Area designations may be recorded in each subscriber's home location register (HLR); however, IS-41 makes no provision for this function and an existing system is limited to transporting 1,024 different areas between the HLR and the mobile switching center (MSC). This may cover the need for today's market, but when the need arises to provide a Home area for each subscriber, the number of different areas will increase significantly, and may reach several hundred thousand to a million different Home areas for each HLR.
It may be possible to accomodate this need using today's technology, but such a solution suffers from several severe disadvantages. First, the Home area information for each mobile subscriber must be passed to visited MSCs whenever the subscriber designates a Home area and a Work area (or a second Home area) in a different exchange controlled by a different MSC. Second, since the number of subscribers who will require this service cannot be accurately estimated, the design of future HLRs is uncertain. Third, the administration of this home area data becomes extremely difficult, and requires large amounts of data handling resources when the number of subscribers gets very large. HLR administrators must pass data to visited MSCs defining the Home areas of potentially millions of subscribers, and must keep track of the different rates charged each subscriber at different times and in different areas.
One possible solution to simplify the data handling problem is to designate each subscriber's Home area simply as the Cell in which the subscriber's residence or office is located. However, this solution poses several problems. First, as system capacity increases, additional cells are added and individual cell sizes become smaller. Therefore an operator may have to designate several cells instead of a single cell to represent the Home area of some subscribers. Second, cell planning requires the redistribution of cells from time to time as population growth in some areas exceeds local cell limitations. Thus, the cell information of each subscriber would have to be changed to reflect the new cell planning information. Finally, under existing cellular telecommunications standards, the HLR does not record any specific cell information. Instead, the geographic disposition of cells is handled by the mobile switching centers (MSCs).
Although there are no known prior art teachings of a solution to the aforementioned deficiencies, a number of prior art references exist that discuss subject matter that bears some relation to matters discussed herein. Such prior art references are U.S. Pat. Nos. 5,327,144 to Stilp et al., 5,235,633 to Dennison et al., and 5,043,736 to Damell et al. Each of these references is discussed briefly below.
U.S. Pat. No. 5,327,144 to Stilp et al. (Stilp) discloses a cellular telephone locating system. Stilp calculates the location of mobile stations operating within a given area by measuring the differences in times of arrival of mobile station transmissions at several cell sites. Stilp suggests that location data may be merged with billing data to generate modified billing data, for example, lower rates when calling from a particular geographic locale. However, Stilp only discloses means for locating mobile stations, but does not disclose any means for establishing and administering geographic areas within a cellular telecommunications network. Additionally, Stilp does not disclose any means for defining and administering personal home areas on an individual subscriber basis.
U.S. Pat. No. 5,235,633 to Dennison et al. discloses a cellular telephone system that uses the geographic location of a mobile station to make call management decisions such as selection of a cell site most appropriate for the mobile station. The geographic location of the mobile station is determined using a NAVSTAR global positioning system (GPS) or its equivalent. However, like Stilp above, Dennison does not disclose any means for establishing and administering geographic areas within a cellular telecommunications network.
Finally, U.S. Pat. No. 5,043,736 to Darnell et al. discloses a cellular position locating system for locating the geographic coordinates of a person at a remote location using a portable hand-held unit and a cellular telephone system. However, like Stilp and Dennison above, Darnell does not disclose any means for establishing and administering geographic areas within a cellular telecommunications network.
Review of each of the foregoing references reveals no disclosure or suggestion of a system or method such as that described and claimed herein. It would be a distinct advantage to have a system and method for defining personal home areas for individual subscribers of cellular telecommunications services that establishes and administers personalized geographic areas within a cellular telecommunications network in an efficient manner with a minimum of data handling resources. The present invention provides such a system and method.